Coated article for hot hydrocarbon fluid and method of preventing fuel thermal degradation deposits

ABSTRACT

A hydrocarbon fluid containment article having a wall with a surface that is wetted by hydrocarbon fluid. The surface includes an anti-coking coating. The anti-coking coating includes a copper salt, a silver salt, or a combination thereof. A gas turbine engine component including a wall having a first surface and an anti-coking coating on the first surface of the wall that is wetted by hydrocarbon fluid. The anti-coking coating including a copper salt, a silver salt, or a combination thereof that prevents the formation of gum or coke on a surface thereon. Methods for reducing the deposition of thermal decomposition products on a wall of an article are also provided.

FIELD

The present disclosure generally relates to an article and a turbineengine component having an anti-coking coating thereon. The presentdisclosure also relates to methods for preventing or reducing thedeposition of thermal decomposition products on surfaces in contact witha hydrocarbon fluid.

BACKGROUND

Coke deposition is a common issue in aircraft fuel and lubricationsystems exposed to high temperatures. Coke deposition can be caused bythe catalytic-thermal degradation of hydrocarbon fluids, resulting incarbon becoming attached and building up as deposits on surfacescontacted by a fuel or oil. Carbon deposits may develop if the fluidcircuit is operated at reduced flow rates or closed without theremaining stagnant fuel being purged. As the deposits collect, they canbecome sufficiently large to reduce or even obstruct fluid flow. In thecase of a fuel circuit, such carbon deposition can lead to degradedengine performance, reduced heat transfer efficiencies, increasedpressure drops, and increased rates of material corrosion and erosion,all of which can necessitate the use of expensive de-coking procedures.

Accordingly, improvements for preventing the formation and deposition ofgum and coke deposits would be desirable.

BRIEF DESCRIPTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description or may belearned through practice of the invention.

In one aspect, embodiments of the present disclosure relate to ahydrocarbon fluid containment article through which a hydrocarbon fluidflows. The hydrocarbon fluid containment article includes a wall havinga first surface and an anti-coking coating on the first surface of thewall that is wetted by the hydrocarbon fluid. The anti-coking coatingincludes a copper salt, a silver salt, or a combination thereof. Theanti-coking coating prevents the formation of gum or coke on a surfacethereon.

In one aspect, embodiments of the present disclosure are directed to agas turbine engine component including a wall having a first surface andan anti-coking coating on the first surface of the wall that is wettedby the hydrocarbon fluid. The anti-coking coating including a coppersalt, a silver salt, or a combination thereof, the hydrocarbon fluidcontacting and flowing across the anti-coking coating, the anti-cokingcoating preventing the formation of gum or coke thereon.

In another aspect, embodiments of the present disclosure relate to amethod for reducing deposition of thermal decomposition products on awall of an article containing a hydrocarbon fluid at temperatures above105° C. The method includes depositing an anti-coking coating on a firstsurface of the wall of the article that is wetted by the hydrocarbonfuel. The anti-coking coating includes a copper salt, a silver salt, ora combination thereof, the hydrocarbon fluid contacting and flowingacross the anti-coking coating, the anti-coking coating preventing theformation of gum or coke thereon.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompany drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with this description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will become more apparent in light of the subsequent detaileddescription when taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a partial longitudinal view of a high pressure turbine nozzlefor a jet engine fueled by distillate fuel incorporating the anti-cokingcoating disclosed herein; and

FIG. 2 is a section view taken along lines of II-II of FIG. 1 showingfuel containment passages for circulating distillate fuel.

DETAILED DESCRIPTION

One or more embodiments of the present disclosure will be describedbelow. Unless defined otherwise, technical and scientific terms usedherein have the same meaning as is commonly understood by one ofordinary skill in the art to which this disclosure belongs.

The terms “a” and “an” do not denote a limitation of quantity, butrather denote the presence of at least one of the referenced items.Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about”, are not to be limited to the precise valuespecified. Additionally, when using an expression of “about a firstvalue—a second value,” the about is intended to modify both values. Inat least some instances, the approximating language may correspond tothe precision of an instrument for measuring the value.

Here, and throughout the specification and claims, range limitations maybe combined and/or interchanged, such ranges are identified and includeall the sub-ranges contained therein unless context or languageindicates otherwise. Any numerical values recited herein include allvalues from the lower value to the upper value in increments of one unitprovided that there is a separation of at least 2 units between anylower value and any higher value. As an example, if it is stated thatthe amount of a component or a value of a process variable such as, forexample, temperature, pressure, time and the like is, for example, from1 to 90, it is intended that values such as 15 to 85, 22 to 68, 43 to51, 30 to 32 etc. are expressly enumerated in this specification. Forvalues which are less than one, one unit is considered to be 0.0001,0.001, 0.01 or 0.1 as appropriate. These are only examples of what isspecifically intended and all possible combinations of numerical valuesbetween the lowest value and the highest value enumerated are to beconsidered to be expressly stated in this application in a similarmanner.

The anti-coking coating and methods of the present disclosure caninclude, consist essentially of, or consist of, the components of thepresent disclosure as well as other materials described herein. As usedherein, “consisting essentially of” means that the composition orcomponent may include additional materials, but only if the additionalmaterials to not materially alter the basic and novel characteristics ofthe claimed composition or methods.

The terms hydrocarbon fluid, hydrocarbon fuel and distillate fuel may beused interchangeably herein.

Generally, the present subject matter provides an article, such ashydrocarbon fluid containment article through which a hydrocarbon fluidflows. Surfaces of the article wetted by the hydrocarbon fluid includean anti-coking coating. The anti-coking coating includes a copper salt,a silver salt, or a combination thereof. The anti-coking coatingprevents the formation of gum or coke thereon. Gas turbine enginecomponents including the anti-coking coating and methods for reducingdeposition of thermal decomposition products on the wall of an articleare also provided.

The disclosure has applicability to any hydrocarbon fluid or fuel inwhich gum, coke and/or sulfur compounds form when the fluid is exposedto heat. Indeed, thermal instability or fuel instability refers to theformation of undesired deposits that occurs when hydrocarbon fluids areexposed to high temperatures, generally those above about 140° C. Twodistinct mechanisms contribute to the formation of carbonaceoussubstances. The first mechanism, referred to as the coking process,produces a consistent increase in the rate of coke formation and cokedeposits at temperatures of about 650° F. (about 345° C.) or greater.Coke formation results from high levels of hydrocarbon pyrolysis, andeventually limits the usefulness of the fuel. The second mechanismprimarily occurs at lower temperatures, generally in the range of about220° F. to about 650° F. (about 105° C. to about 345° C.) and involvesoxidation reactions that lead to polymerization and carbonaceous gumdeposits. Both coke and gum formation can occur simultaneously in themid-temperature region. Given operating temperatures of certain engines,such as gas turbine engines, gum and coke deposits can form onhydrocarbon wetted surfaces. Accordingly, the anti-coking coatingdisclosed herein prevents the formation of gum and certain cokesubstances in hydrocarbon fuels and further prevents the adherence ofgum and certain coke substances on surfaces exposed to hydrocarbonfuels.

A fluid containment article is shown in FIG. 1 which represents a heatexchanger for cooling the high pressure turbine nozzle of a jet engineby transferring the heat generated therein to liquid hydrocarbon fuelconfined in and transported through conduits or chambers adjacent thenozzle wall.

In FIG. 1, liquid hydrocarbon fuel enters the high pressure turbinenozzle at conduit 6 and passes through passageway 2 where heat fromcombustion chamber 16 is cooled by the liquid hydrocarbon fuel passingthrough passageway 2. Heat exchange occurs between the walls ofcombustion chamber 16 and the liquid hydrocarbon fuel passing throughpassageway 2. In certain instances, the walls of the nozzle which formcombustion chamber 16 have an operating temperature of up to about 1200°F. (about 649° C.). Similarly, hydrocarbon fuel also enters passageway 4at conduit 8 and passes through passageway 4 where heat exchange alsooccurs between the wall of combustion chamber 16 and the hydrocarbonfuel in passageway 4. Heated and vaporized hydrocarbon fuel 12 flowsinto combustion chamber 16 through gas injection ports 10.

FIG. 2 illustrates the fuel containment passageway 2 of FIG. 1 beingtaken along the lines II-II of FIG. 1. As shown, passageway 2 containswalls 24 and 26 in which fuel passageway 22 is formed. The anti-cokingcoating 20 of the present disclosure is coated on substrate materialforming walls 24 and 26 so that it forms an anti-coking coating 20 overthe substrate surfaces of passageway 22. Substrate materials for walls24 and 26 may be stainless steel, corrosion-resistant alloys of nickeland chromium, high-strength, corrosion-resistant nickel-base alloys,cobalt-base alloys, and the like. These substrate materials cause orpromote the formation of fuel thermal degradation products, such as gum,coke and/or sulfur compounds or mixtures thereof, in hydrocarbon fluidsand fuels. Hydrocarbon fuel is transported through passageway 22 andcontacts the anti-coking coating 20 disposed on walls 24 and 26.

In embodiments, the anti-coking coating 20 is catalytically active andcatalyzes the fuel to promote the formation of a loosely-adherent ornon-adherent coke in the hydrocarbon fluid. For instance, theanti-coking coating 20 promotes the formation of coke substances that donot adhere to or undergo additional polymerization along passageway 22.The anti-coking coating 20 is sufficient to prevent the formation ofdeposits resulting from sulfur, oxygen, and mixtures thereof inhydrocarbon fuel with metal atoms along the surfaces of passageway 22.Thus, the anti-coking coating 20 promotes the formation of certain cokeproducts while simultaneously inhibiting the formation of gum products,which prevent, reduce or inhibit the deposition of gum along passageway22. The loosely-adherent or non-adherent coke products remain suspendedor dispersed in the fuel where it is then transported with the fuel tothe combustor for burning.

In addition to its catalytic activity, the anti-coking coating 20 mayalso provide a physical diffusion barrier between the substrate materialof walls 24 and 26 and the hydrocarbon fuel. More specifically, theanti-coking coating 20 can also provide a physical diffusion barrierpreventing certain metal atoms from migrating from the walls 24 and 26into the hydrocarbon fuel.

The anti-coking coating 20 can include one or more coating materialssuch as metal salts. Such metal salts can include one or more coppersalts, one or more aluminum salts, or combinations thereof. For example,the anti-coking coating 20 can include copper (II) sulfate, copper (II)nitrate, copper (II) chloride, copper (II) chloride anhydrous, copper(II) chloride dihydrate, or combinations thereof. In embodiments, theanti-coking coating 20 can include one or more silver salts such assilver chloride, silver fluoride, silver nitrate, silver sulfate, andcombinations thereof.

The anti-coking coating 20 as applied can have a coating thicknessranging from about 0.5 μm to about 10 μm, such as from about 1 μm toabout 9 μm, such as from about 2 μm to about 8 μm, such as from about 3μm to about 7 μm, such as from about 4 μm to about 6 μm.

Although the disclosure is not directed to or limited by any particularhydrocarbon fluid or hydrocarbon fuel, typical fuels for which themethod and fluid containment and other articles of the presentdisclosure are adapted, and typical fuels from which the substrates offluid containment articles are protected in accordance with the presentdisclosure, are the combustible hydrocarbon gases, such as natural gas,and the hydrocarbon or distillate fuels generally discussed above andinclude hydrocarbons and distillation products thereof which aregenerally liquid at room temperature. The fluids may be mixtures ofhydrocarbons, mixtures of such distillation products, mixtures ofhydrocarbons and distillation products, gasoline, No. 1 or No. 2 dieselfuels, jet engine fuels, such as Jet-A fuel, or the foregoing fuelsmixed with additives which are well-known in the art. Hydrocarbon fuelsrefer to the liquid fuels which are conventionally used in reactionmotors, including but not limited to, industrial gas turbines, enginesused in internal combustion engines, including but not limited toautomobile and truck engines, jet propelled aircraft or any other gasturbine engine, all of which are conventionally known in the art.

The articles of the present disclosure may be any component that isadapted to contact or contain hot hydrocarbon fluid, for example, liquidhydrocarbon jet engine or diesel fuel, heated to a temperature at whichdegradation products form in hydrocarbons, hydrocarbons circulating inconduits, heat exchangers and the like, of refineries, polymer plantsand power plants, furnaces and the like. Such articles for containinghot hydrocarbon fluid are defined herein as fluid containment articles.Examples of such fluid containment articles are discussed above andinclude any device in which hot hydrocarbon fluid can be confined,stored, transported or otherwise subjected to heat exchange withoutignition or combustion of the hot fluid. The present disclosure isparticularly adaptable to heat transfer surfaces where heat istransferred from a combustor or other heat source through a wall toliquid hydrocarbon fluid. Specific examples of articles for containingor contacting hot hydrocarbon fluids in accordance with the presentdisclosure include fuel storage tanks, conduits for transporting liquidfuel, coils and other devices for heat exchange contact with fuel, fuelinjector surfaces, nozzles and the like.

Other articles which may be coated with the anti-coking coating 20 ofthe present disclosure, include automobile and truck engine parts whichare exposed to hot hydrocarbon fuel, e.g., gasoline, natural gas, dieselfuel and the like, including parts of engines in which air and fuel aremixed and/or atomized and/or vaporized. These parts include valves,cylinders, fuel injectors, fuel atomizers, combustion chambers and thelike.

The anti-coking coating 20 can be applied to the desired substrate viaany suitable process. Suitable coating processes include, but are notlimited to dipping, soaking, spraying, painting, flowing, or using anyother process suitable to apply the anti-coking coating to the article.

In certain embodiments, the anti-coking coating can be applied viasubmerging the article in solution containing one or more metal salts.For example, the article formed of a metal substrate having one or morehydrocarbon fuel wetting surfaces thereon, such as a fuel nozzle can befabricated and assemble. The assembled article can then be exposed to asolution containing one or metal salts. The solution can also includeone or more solvents, such as one or more polar organic solvents.Non-limiting examples of polar organic solvents suitable for use includeelastomers, such as esters, ketones, ethers, alcohols, or combinationsthereof. A solvent recirculation system can be utilized to facilitatecoating of the article. A salt control system capable of maintaining theconcentration of the metal salt in solution can also be utilized. Forexample, the metal salt in solution can be maintained at saturation orat any other desired level during the coating process. Dipping and/orsoaking the article in such a manner allows for the metal salt to beapplied to metal surfaces throughout the article. The article can beexposed to the solution containing one or more metal salts until thedesired level or thickness of coating on the article is achieved. Thecoated article can then be removed from the recirculation system, purgedwith any suitable inert gas, and dried to remove any remaining solvent.

Advantageously, utilizing a dipping or soaking method to apply theanti-coking coating allows for an even application of the coating onhard-to-reach or rough surfaces of the article. Certain hydrocarbonfluid containment articles can include internal surfaces having smallorifices, bent projections, rough surfaces, etc., that can make coatingthe article via line-of-sight application processes very difficult ifnot nearly impossible. The disclosed soaking method, however, includescirculating solution containing the anti-coking coating material suchthat the solution flows in and across the surfaces of the articleallowing for the fluid to penetrate and coat rough or hard-to-reachsurfaces. Furthermore, no sub-coatings, pre-treatment coatings, orsurface preparation of the article is necessary prior to applying theanti-coking coating disclosed herein, which simplifies manufacturing ofthe article and can reduce manufacturing costs and waste. For example,the application surface of the article does not need to be polished to acertain smoothness nor do native oxide residues or layers on the articleneed to be removed prior to applying the anti-coking coating disclosedherein.

During coating it is contemplated that other surfaces of the article,such as external surfaces may be coated with the anti-coking coating dueto overspray or immersion of the entire article in the recirculationsystem. Typically, such additional coating of the article is allowed andwill not affect the article during operation. However, portions of theanti-coking coating can be removed from undesired surfaces of thearticle via any suitable mechanical or chemical removal process, such asgrit blasting. Additionally, certain external surfaces can be maskedprior to subjecting the article to the coating process, such that themasked surfaces are not coated by the anti-coking coating.

Given certain materials in the anti-coking coating (e.g., copper salts),the anti-coking coating material may be applied to the article in anisolated environment. For instance, the anti-coking coating can bedeposited on the wall of the article in a separate facility from wherethe remaining fuel system is assembled and manufactured. Such facilityisolation or separation may be desired so that the anti-coking coatingmaterials disclosed herein do not contaminate the rest of the facilityin which remaining parts of the entire fuel assembly are assembled.Further, it is contemplated that the anti-coking coating material can beapplied to the article in the same manufacturing facility, as long asthe coating process is completed in an isolated manner such thatanti-coking coating materials do not contaminate the manufacturingfacility.

Example embodiments, also provide a method for reducing deposition ofthermal decomposition products on a wall of an article containing ahydrocarbon fluid at temperatures above 300° C. The method comprisingthe step of depositing a coating on the wall of the article, the coatingcomprising an anti-coking coating protecting the wall from chemicalattack by constituents in the hydrocarbon fluid. The anti-coking coatingincludes one or more metal salts, such as copper (II) chloride, copper(II) chloride anhydrous, copper (II) chloride dihydrate, or combinationsthereof. The anti-coking coating catalyzes the hydrocarbon fluid to formparticulates of carbonaceous gum substances or coke suspended within thehydrocarbon fluid that are non-adherent or loosely-adherent to theanti-coking coating such that the formation or adhesion of gum on thewall of the article is prevented.

Although the present disclosure has utility in any fuel containmentarticle or in any fuel containment system in which fuel does not undergocombustion, and it is particularly useful in forming a catalytic coatingin fuel containment articles and fuel containment systems wherein thefuel is used as a heat exchange medium to remove heat from varioussystems in gas turbines, both industrial and those used in aircraft andthe like, it is particularly useful in the heat exchanger surfaces infuel systems of a gas turbine, a scramjet engine, a ramjet engine, or aturbojet engine or as a conduit for transporting heated hydrocarbon fuelin a fuel system of any of the foregoing.

Further aspects of the invention are provided by the subject matter ofthe following clauses:

1. A hydrocarbon fluid containment article through which a hydrocarbonfluid flows, the hydrocarbon fluid containment article comprising: awall having a first surface and an anti-coking coating on the firstsurface of the wall that is wetted by the hydrocarbon fluid, theanti-coking coating comprising a copper salt, a silver salt, or acombination thereof, the hydrocarbon fluid contacting and flowing acrossthe anti-coking coating, the anti-coking coating preventing theformation of gum or coke thereon.

2. The article of any preceding clause wherein the copper salt or silversalt of the anti-coking coating catalyzes the hydrocarbon fluid to formparticulates of carbonaceous gum or coke suspended within thehydrocarbon fluid that are non-adherent or loosely-adherent to theanti-coking coating.

3. The article of any preceding clause wherein the copper salt comprisescopper (II) sulfate, copper (II) nitrate, copper (II) chloride, copper(II) chloride anhydrous, copper (II) chloride dihydrate, or combinationsthereof.

4. The article of any preceding clause wherein the silver salt comprisessilver chloride, silver fluoride, silver nitrate, silver sulfate, orcombinations thereof.

5. The article of any preceding clause wherein the wall comprises ametal surface.

6. The article of any preceding clause wherein the anti-coking coatinghas a thickness of from about 0.5 μm to about 10 μm.

7. The article of any preceding clause wherein the anti-coking coatingis deposited on the wall by dipping or soaking the article in a liquidcontaining a copper salt, silver salt, or combinations thereof to coatthe first surface of the wall throughout the article.

8. The article of any preceding clause wherein the hydrocarbon fluid isat a temperature of about 105° C. to about 345° C.

9. The article of any preceding clause wherein the article is a gasturbine engine component.

10. The article of any preceding clause wherein the gas turbine enginecomponent comprises fuel/air heat exchangers, pipes, fuel nozzles, oilsumps, or combinations thereof.

11. A gas turbine engine component comprising: a wall having a firstsurface and an anti-coking coating on the first surface of the wall thatis wetted by the hydrocarbon fluid, the anti-coking coating comprising acopper salt, a silver salt, or a combination thereof, the hydrocarbonfluid contacting and flowing across the anti-coking coating, theanti-coking coating preventing the formation of gum or coke thereon.

12. The component of any preceding clause wherein the copper salt orsilver salt of the anti-coking coating catalyzes the hydrocarbon fluidto form particulates of carbonaceous gum substances or coke suspendedwithin the hydrocarbon fluid that are non-adherent or loosely-adherentto the anti-coking coating.

13. The component of any preceding clause wherein the copper saltcomprises copper (II) sulfate, copper (II) nitrate, copper (II)chloride, copper (II) chloride anhydrous, copper (II) chloridedihydrate, or combinations thereof.

14. The component of any preceding clause wherein the silver saltcomprises silver chloride, silver fluoride, silver nitrate, silversulfate, and combinations thereof.

15. The component of any preceding clause wherein the first surface ofthe wall comprises a metal surface such as an iron-, nickel-, orchromium-containing metal surface.

16. The component of any preceding clause wherein the anti-cokingcoating has a thickness of from about 0.5 μm to about 10 μm.

17. The component of any preceding clause wherein the hydrocarbon fluidis at a temperature of about 150° C. to about 450° C.

18. The component of any preceding clause wherein the componentcomprises fuel/air heat exchangers, pipes, fuel nozzles, oil sumps, andcombinations thereof.

19. A method for reducing deposition of thermal decomposition productson a wall of an article containing a hydrocarbon fluid at temperaturesabove 105° C. comprising, depositing an anti-coking coating on a firstsurface of the wall of the article that is wetted by the hydrocarbonfuel, the anti-coking coating comprising a copper salt, a silver salt,or a combination thereof, the hydrocarbon fluid contacting and flowingacross the anti-coking coating, the anti-coking coating preventing theformation of gum or coke thereon.

20. The method of any preceding clause wherein deposition theanti-coking coating on the first surface of the wall of the article isperformed in an isolated environment.

This written description uses examples to describe the disclosure,including the best mode, and also to enable any person skilled in theart to practice the disclosure, including making and using any devicesor systems and performing any incorporated methods. The patentable scopeof the disclosure is defined by the claims, and may include otherexamples that occur to those skilled in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal languages of the claims.

1. A hydrocarbon fluid containment article through which a hydrocarbonfluid flows, the hydrocarbon fluid containment article comprising: awall having a first surface and an anti-coking coating on the firstsurface of the wall that is wetted by the hydrocarbon fluid, theanti-coking coating comprising a copper salt, a silver salt, or acombination thereof, the hydrocarbon fluid contacting and flowing acrossthe anti-coking coating, the anti-coking coating preventing theformation of gum or coke thereon.
 2. The article of claim 1, wherein thecopper salt or silver salt of the anti-coking coating catalyzes thehydrocarbon fluid to form particulates of carbonaceous gum or cokesuspended within the hydrocarbon fluid that are non-adherent orloosely-adherent to the anti-coking coating.
 3. The article of claim 1,wherein the copper salt comprises copper (II) sulfate, copper (II)nitrate, copper (II) chloride, copper (II) chloride anhydrous, copper(II) chloride dihydrate, or combinations thereof.
 4. The article ofclaim 1, wherein the silver salt comprises silver chloride, silverfluoride, silver nitrate, silver sulfate, or combinations thereof. 5.The article of claim 1, wherein the wall comprises a metal surface. 6.The article of claim 1, wherein the anti-coking coating has a thicknessof from about 0.5 μm to about 10 μm.
 7. The article of claim 1, whereinthe anti-coking coating is deposited on the wall by dipping or soakingthe article in a liquid containing a copper salt, silver salt, orcombinations thereof to coat the first surface of the wall throughoutthe article.
 8. The article of claim 1, wherein the hydrocarbon fluid isat a temperature of about 105° C. to about 345° C.
 9. The article ofclaim 1, wherein the article is a gas turbine engine component.
 10. Thearticle of claim 9, wherein the gas turbine engine component comprisesfuel/air heat exchangers, pipes, fuel nozzles, oil sumps, orcombinations thereof.
 11. A gas turbine engine component comprising: awall having a first surface and an anti-coking coating on the firstsurface of the wall that is wetted by the hydrocarbon fluid, theanti-coking coating comprising a copper salt, a silver salt, or acombination thereof, the hydrocarbon fluid contacting and flowing acrossthe anti-coking coating, the anti-coking coating preventing theformation of gum or coke thereon.
 12. The component of claim 11, whereinthe copper salt or silver salt of the anti-coking coating catalyzes thehydrocarbon fluid to form particulates of carbonaceous gum substances orcoke suspended within the hydrocarbon fluid that are non-adherent orloosely-adherent to the anti-coking coating.
 13. The component of claim11, wherein the copper salt comprises copper (II) sulfate, copper (II)nitrate, copper (II) chloride, copper (II) chloride anhydrous, copper(II) chloride dihydrate, or combinations thereof.
 14. The component ofclaim 11, wherein the silver salt comprises silver chloride, silverfluoride, silver nitrate, silver sulfate, and combinations thereof. 15.The component of claim 11, wherein the first surface of the wallcomprises a metal surface such as an iron-, nickel-, orchromium-containing metal surface.
 16. The component of claim 11,wherein the anti-coking coating has a thickness of from about 0.5 μm toabout 10 μm.
 17. The component of claim 11, wherein the hydrocarbonfluid is at a temperature of about 150° C. to about 450° C.
 18. Thecomponent of claim 11, wherein the component comprises fuel/air heatexchangers, pipes, fuel nozzles, oil sumps, and combinations thereof.19. A method for reducing deposition of thermal decomposition productson a wall of an article containing a hydrocarbon fluid at temperaturesabove 105° C. comprising, depositing an anti-coking coating on a firstsurface of the wall of the article that is wetted by the hydrocarbonfuel, the anti-coking coating comprising a copper salt, a silver salt,or a combination thereof, the hydrocarbon fluid contacting and flowingacross the anti-coking coating, the anti-coking coating preventing theformation of gum or coke thereon.
 20. The method of claim 19, whereindeposition the anti-coking coating on the first surface of the wall ofthe article is performed in an isolated environment.